176 MORPHOLOGY AND EVOLUTION
the vertebral border of the scapula. The following list gives the recorded observations regarding its origin :—
Gibbon (Hi/lobates muelleri] : cervical vertebrse 1 to 4 i Sonntag 399),
Orang: five slips of origin (Fick 247).
Chimpanzee : atlas and axis \Champneys 318) ; cervical vertebrae 2 and 3 iGratioIet 330) ; cervical vertebrae 1 to 3 (Hepburn 83); cervical vertebrse 1 to 4 (Wilder 414; Sonntag 399); first five cervical vertebrae (Bland-Sutton 402j.
Gorilla : four slips of origin (Hepburn 83) ; five slips of origin (Sominer 493).
The serratus posticus superior (fig. 33) runs from the lower cervical and upper dorsal spines to ribs 1 to 4 or 2 to 5. The serratus posticus inferior in the Gibbon, Orang and Chimpanzee runs from the posterior lamella of the lumbar fascia to a variable number of lower ribs. It is absent in most Gorillas, but Duvernoy (53) saw it in his specimen. Seydel (146) made a thorough study of the posterior serrate muscles.
The splenius (fig. 33) is a powerful muscle, particularly the splenius capitis. In the Chimpanzee its origin varies, sometimes extending from the spine of the axis to the seventh dorsal spine. The splenius ccvpitis (Spl. Cap.) is inserted into the mastoid process and outer half or third of the occipital crest. The splenius cervicis (Sple. Cer.) forms one to four slips inserted into the first one to four cervical transverse processes. There is a variable degree of fusion with the neighbouring cervical muscles. In the Gorilla there are one to three slips, and in the Gibbon. The splenius cervicis is absent in the Orang.